Contents List of Theorems,Lemmas,and Corollaries xix Preface xxi CHAPTER 1 Counting 1 1.1 Basic Counting 1 The Sum Principle 1 Abstraction 3 Summing Consecutive Integers 3 The Product Principle 4 Two-Element Subsets 6 Important Concepts,Formulas,and Theorems 7 Problems 8 1.2 Counting Lists,Permutations,and Subsets 10 Using the Sum and Product Principles 10 Lists and Functions 12 The Bijection Principle 14 k-Element Permutations of a Set 15 Counting Subsets of a Set 16 Important Concepts,Formulas,and Theorems 18 Problems 20 1.3 Binomial Coefficients 22 Pascal's Triangle 22 A Proof Using the Sum Principle 24 The Binomial Theorem 26 Labeling and Trinomial Coefficients 28 Important Concepts,Formulas,and Theorems 29 Problems 30 ixContents List of Theorems, Lemmas, and Corollaries xix Preface xxi CHAPTER 1 Counting 1 1.1 Basic Counting 1 The Sum Principle 1 Abstraction 3 Summing Consecutive Integers 3 The Product Principle 4 Two-Element Subsets 6 Important Concepts, Formulas, and Theorems 7 Problems 8 1.2 Counting Lists, Permutations, and Subsets 10 Using the Sum and Product Principles 10 Lists and Functions 12 The Bijection Principle 14 k-Element Permutations of a Set 15 Counting Subsets of a Set 16 Important Concepts, Formulas, and Theorems 18 Problems 20 1.3 Binomial Coefficients 22 Pascal’s Triangle 22 A Proof Using the Sum Principle 24 The Binomial Theorem 26 Labeling and Trinomial Coefficients 28 Important Concepts, Formulas, and Theorems 29 Problems 30 ix